Anti-jack knife device



June 27, 1967 F. J. c. HOPE ET Al. 3,328,051

ANTI -JACK KNIFE DEVICE Filed May 13, 1966 6 Sheets-Sheet 1 INVENTORS FREDERICK JOHN CHARLES HOPE FREDERICK GEORGE LAMBERT MORGAN, FINNEGAN, DURHAM 8x PINE ATTORNEYS June 27, 1967 F, J. c. HOPE ET AL ANTI-JACK KNIFE DEVICE 6 Sheets-Sheet 5 Filed May 15, 1966 INVENTORS FREDERICK JOHN CHARLES HOPE FREDERICK GEORGE LAMBERT MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS June 27, 1967 J c, HOPE ETA], 3,328,051

ANTI-JACK KNIFE DEVICE Filed May 13, 1966 6 Sheets-Sheet 4 INVENTORS FREDERICK JOHN CHARLES HOPE FREDERICK GEORGE LAMBERT MORGAN, FINNEGAN. DURHAM a PINE ATTORNEYS June 27, 1967 v F. J. c. HOPE ET AL 3,328,051

ANTI-JACK KNIFE DEVICE Filed May 13, 1966 6 Sheets-Sheet 5 INVENTORS FREDERICK JOHN CHARLES HOPE I BY FREDERICK GEORGE LAMBERT MORGAN, FINNEGAN, DURHAM 8 PINE ATTORNEYS J1me 1967 F. J. c. HOPE ET AL ANTI-JACK KNIFE DEVICE 6 Sheets-Sheet 6 Filed May 15, 1966 m6 mQm POM m J f DOW wow 0pm wOm MO INVENTORS FREDERICK JOHN CHARLES HOPE BY FREDERICK GEORGE LAMBERT MORGAN, FINNEGAN, DURHAM 8| PINE ATTORNEYS United States Patent 3,328,051 ANTI-JACK KNIFE DEVICE Frederick John Charles Hope, 20 New Road, Datchet,

Buckinghamshire, England, and Frederick George Lambert, 24 Tekels Way, Camberley, Surrey, England Filed May 13, 1966, Ser. No. 550,032

Claims priority, application Great Britain, Aug. 29, 1963, 34,290/ 63; Oct. 8, 1963, 39,705/63; Oct. 28, 1963, 42,484/63; Oct. 29, 1963, 42,706/63; Mar. 2, 1964, 8,750/ 64; May 14, 1965, 20,456/ 65 14 Claims. (Cl. 280432) The invention relates to anti-jack knife devices for use with fifth wheel couplings on articulated vehicles. This application is a continuation in part of application Ser. No. 392,887, Anti-Jack Knife Device, filed Aug. 28, 1964, and now abandoned.

It is among the objects of the invention to provide means for resisting the relative jack-knife movement between the tractor and trailer of an articulated or like vehicle which is liable to occur during application of the vehicle road wheel brakes.

A number of previous attempts have been made to overcome the dangerous phenomenon of jack knifing which quite commonly occurs with articulated vehicles when braking on a wet or greasy road surface. Prior attempts to solve the problem have however tended to concentrate on devising a system of rigidly locking the trailer and tractor together to stop jack knifing occurring so that the tractor and trailer were rigidly locked together at ,a particular pivotal angle. This prior art type of antijack knife device however introduces additional dangers since if a trailer and tractor are rigidly locked together the driver loses control of the vehicle because the trailer tends to steer the vehicle in the manner of a rudder of a boat. Since the most convenient method of actuating an anti-jack knife device is to link it with the braking system of the articulated vehicle, the prior art devices would also result in the driver losing control of the vehicle when braking in an emergency while trying to avoid an obstacle in the road.

-We have now made the unexpected discovery that if a brake having flat braking surfaces is employed as they basis for an anti-jack knife device, pivotal movement of the trailer relative to the tract-or can be retarded so as to effectively prevent jack-knifing occurring without any danger of the trailer becoming rigidly locked to the tractor.

In one form of the invention an anti-jack knife device is arranged to be readily fitted to a trailer and its coupling pin is adapted to fit the standard fifth wheel coupling which has now been accepted in the commercial vehicle and haulage industry so that there is no necessity to use the device of the present invention with a special matched tractor coupling.

In an alternative form of the invention, the anti-jack knife device is housed in a fifth wheel assembly which is rotatably mounted on the tractor and the coupling pin fixedly secured to the trailer in conventional manner so that the fifth wheel rotates with the trailer.

According to a feature of the invention the anti-jack knife device may include a coupling pin h-aving, attached to its lower end, a lateral tongue which is adapted to engage in' the slot of a standard fifth wheel in order to prevent rotational movement. The tongue may be secured to the coupling pin by welding or formed integrally .with the pin. Alternatively a separate pin may be provided on the tractor or trailer and arranged to engage with a corresponding recess on the corresponding part of the vehicle.

In a preferred form of the invention the coupling pin is carried in the trailer and carries at its upper end a plurality of first annular discs which are slidably but nonrotatably mounted on the pin. Interposed between at least one pair of adjacent discs is a second annular disc which is slidably but non-rotatably attached to the trailer, means being provided for compressing the stack of discs together thereby resisting turning movement of the coupling pin.

Preferably the discs are contained within a casing which is secured to the trailer and the second disc or discs are attached to the casing. The means for compressing the stack of discs preferably comprises an annular piston member disposed in the casing above or below the stack of discs. The piston member may be movable to compress the discs by means of fluid admitted under pressure into the casing between the piston member and one end of the casing.

According to the invention furthermore the anti-jack knife device may include fluid control means, operable upon articulation of the vehicle to effect and/ or maintain the device in operation.

The fluid control means may comprise a cam attached to the coupling pin which, when the trailer has taken up a predetermined angle with respect to the tractor, cooperates with fluid control valves which control fluid pressure to the operating means for the braking means whereby operation of the braking means is effected and/ or maintained irrespective of whether or not the trailer wheel braking system is operative. Thus removal of the drivers feet from the operating pedals of the brakes will limited operation of the brake actuating pedal, to cause actuation of the anti-jack knife device prior to or without causing the application of the trailer wheel brakes.

Thus a pneumatic wheel braking system for an articulated vehicle may include means, separately connected to and operable under air pressure from the service airline, for applying the braking means of the anti-jack knifedevice, and valve means in the air-line to the trailer wheel brake operating means, which valve means open to pass air at a pressure higher than the operatingpressure of the braking means for the anti-jack knife device.

Release valve means'may also be provided, operable upon disengagement of the anti-jack knife device, to release the vehicle brakes.

The invention may further comprise those features of construction hereinafter described with reference to the accompanying drawings in which:

FIGURE 1 is a sectional elevation of one construction according to the invention;

FIGURE 2 is a plan view of the construction shown in FIGURE 1;

FIGURE 3 is a perspective view of a coupling pin according to the invention;

FIGURE 4 is a diagrammatic elevation of a semi-trailer including a construction according to the invention;

FIGURE 5 is an alternative detail of the construction shown in FIGURE 1;

FIGURE 6 shows a typical fifth wheel in conjunction with which the invention may be used;

FIGURE 7 is a sectional elevation of an alternative construction in accordance with the invention;

FIGURE 8 is a second elevation of a currently pre- FIGURE 11 is a line diagram of a two line pneumatic air braking system incorporating an anti-jack knife device according to the invention;

FIGURE 12 is a sectional elevation of a double check valve of known kind as included diagrammatically in FIGURE 11;

FIGURE 13 is a sectional elevation of a push button control valve of known kind as included diagrammatically in FIGURE 11;

FIGURE 14 is a line diagram of a further two line pneumatic braking system according to the invention;

FIGURE 15 is a line diagram of a three line pneumatic braking system according to the invention,

FIGURE 16 is sectional elevation of a construction in accordance with the invention in which the anti-jack knife device is mounted on the tractor, and

FIGURE 17 is a side elevation of the construction shown in FIGURE 16.

Refer-ring to FIGURES l to 4 of the drawings, 1 is the bottom flange of a channel grider forming part of the chassis of the trailer and carries on its underside a trailer turntable plate 2. The trailer turntable plate 2 carries, on its upper surface, a pin support block 3 and a caliper support block 4. A coupling pin 5 is rotatably mounted in a bore provided in the pin support block 3 and plate 2. The coupling pin 5 has splines 6 at its upper end, on which a brake disc 7 is secured, and an annular groove 8 at its lower end which is engaged with the fifth wheel on the tract-or (FIGURE 6). The braking disc 7 may alternatively be keyed on to the coupling pin 5 shown in FIGURE 5.

In heavy trailers, a further bearing (not shown) may be provided at the upper end of the king pin to prevent rocking.

At a position immediately below the turntable plate 2, laterally extending tongue 9 is welded to the coupling 5, the purpose of which .is explained later.

The caliper support block 4 carries brake caliper 10 which may be of any suitable construction. The lever op erating arm 11 of the caliper is linked mechanically to a piston (not shown) in an air cylinder 12, which is in turn connected with the pneumatic system for the vehicle road wheel brakes under the control of the driver.

'In operation, when the coupling pin 5 is coupled to the fifth wheel (FIGURE 6-) the annular groove 8 engages with a catch 13 and the tongue 9 is retained between the covergent wall 14 of a V slot 15. The annular groove 8 prevents vertical movement, and the tongue 9 rotational movement of the coupling pin 5 relative to the fifth wheel unit. During normal driving conditions, therefore, articulation of the trailer relative to the tractor when the vehicle is negotiating a corner causes the coupling pin 5 and the braking disc 7 to rotate in the pin support block 3 and between the friction surfaces of the caliper 1.

When the driver applies the brakes the air cylinder 12 rotates the lever 11 and causes the caliper 10' to clamp the disc 7. Since the coupling pin 5 is held rigidly relatively to the fifth wheel, articulation and thus jack-knifing of the semi-trailer relative to the tratcor is resisted.

The presently preferred construction of the anti-jack knife device in accordance with the invention is shown in FIGURES 8 and 9. Referring to FIGURES 8 and 9, the coupling pin 5 is similar at its lower end to that shown in FIGURE 1 having a groove 8 for co-operation with the catch 13 in the fifth wheel shown in FIGURE 6 and also a tongue 9 enabling the coupling pin to be ret-ained non-rotatably between the convergent wall 14 of the slot 15 in the fifth wheel shown in FIGURE 6. As shown the tongue 9 carries a downwardly projecting block at the end remote from the coupling pin and this block has the important function of cooperating with the slot 15 in the fifth wheel (see FIGURE 6) and preventing the tongue slipping out of engagement with the slot 15.

The upper part of the coupling'pin 5 is received in a bush 3 secured to the base .2 of the trailer and above the bush 3 an externally splined nut is fixedly secured to the coupling pin 5. The upper part of the coupling pin 5 is enclosed within a casing 111 attached to the base of the trailer and casing 111 includes a cover 112 embodying a bush 113 carrying the uppermost part of coupling pin 5. A stack of annular shaped steel discs 114 are disposed in the annular space between the splined nut 110 and the outer wall of the casing 111 and the inner surfaces of the steel disc 114 are shaped to conform with the splines on the nut 110. Consequently while discs 114 are free to slide vertically up and down the splines of nut 110 they can only rotate about the axis of coupling pin 5 together with nut 110. interposed between discs 114 are a series of friction discs 115 having a surface with a high coefiicient of friction. Discs 115 are fixed with respect to the trailer base 2 by means of studs 116 which pass through holes in discs 115 and are screwed or pressed into the base of the casing. Alternatively discs 115 may be attached to the casing by means of splines formed on their outer periphery which cooperate with splines formed on the inside of the casing. The holes in discs 115 are sufficiently large to allow vertical sliding movement of discs 115 although of course the studs 116 prevent any rotational movement of the discs 115. Mounted above the stack of discs 114 and 115 is a piston member 117 which is annular in shape and is provided with inner and outer O-rin-gs 118 and 119 giving a fluid tight seal at the inner and outer surfaces of the piston member. The cover 112 is provided with one or more inlets 120 enabling fluid under pressure to be admitted to the interior of the casing between the cover and the top surface of the annular piston member 117.

In operation the coupling pin 5 is fitted to a fifth wheel unit as shown in FIGURE 6 in a similar fashion to that described in relation to the device illustrated in FIGURE 1. Thus when in operative condition, the lower part of the coupling pin 5 being non-rotatably coupled to the fifth wheel rotates in accordance with pivotal movement of the trailer and this movement is accommodated by relative movement between the discs 114 and the discs 115. When the anti-jack knife device is operated fluid is admitted under pressure through inlet 120 and this drives piston 117 downwardly with the result that the stack of discs 114 and 115 are compressed together. This action has the effect of resisting rotational movement of discs 114 with respect to discs 115 and consequently the turning movement of coupling pin 5 is resisted.

It will be appreciated that in the alternative the piston 117 can be mounted below the stack of discs 114 and 115 and caused to move upwardly by introduction of fluid under pressure to the base of the casing 111.

In the construction illustrated in FIGURE 7 frictional resistance to resist relative movement between the coupling pin and the trailer is provided by a face plate clutch 25 of single or multiplate design. As shown the clutch plates are set in a housing 26 and a pressure plate 27 and other frictional plates 28 splined to the coupling pin for free axial vertical movement but fixed against rotational movement. Operation may be effected by means of a crank lever 29 connected through linkage to the means for applying the vehicle brakes or by other suitable means of clamping the plates together.

In the construction shown in FIGURE 10 of the drawings, the anti-jack knife device comprises a coupling pin 83 having a lateral extension 84 adapted for engagement in the fifth wheel of the vehicle. The king pin 83 extends upwardly through a bearing 85 in the base 86 of a casing 87 which has, in addition, top and side walls 88 and 89 respectively. The upper end of the king pin 83, which projects into the casing 87, carries a disc 90 secured to the king pin and having a friction material 91 bonded to the upper surface thereof. Within the space above the disc 90 is mounted an annular pressure Plate member 92, the

lower part of the periphery of which is splined with vertical splines 96, the casing 87 being provided with similar splines '93. When fluid pressure is applied through an inlet 94 the member 92 is caused to move downwardly into engagement with the friction material 91 provided on the upper surface of the disc 90. The casing is secured to the rubbing plate 95 of the trailer. As an alternative to splines the plate 92 may be mounted on vertical studs in a similar manner to that shown in FIGURES 8 and 9.

In operation, compressed air is introduced into the cavity in the upper part of the casing 87 through theinlet 94 as by operation of the vehicle brake in known manner.

.The air cavity thus being pressurised causes the pressure plate member 92 to be forced into contact with the friction material 91 secured on the surface of the disc 90. The pressure plate member 92 is prevented from rotating by virtue of the splines '93 and thus brakes the disc and coupling pin so as to prevent relative movement between the tractor and the trailer and the occurrence of jack-knifing. FIGURE 11 of the drawing shows a two-line pneumatic braking system adapted to operate an anti-jack knife device simultaneously with the trailer brakes. A service airline 37 and an emergency air-line 38 are fed in known manner through tractor/trailer couplings 39 and communicate with an emergency relay valve 40. The relay valve 40 controls the su-ply of air to trailer brake air cylinders 41. Also connected to the valve 40 is a reservoir 42 for air under pressure. The reservoir 42 also supplies air to the brake cylinders in the event of failure of the air-lines. An air-line 43 from the service air-line 37 relays service air pressure through a double check valve 44 hereinafter described(FIGURE 12) and a further connection 45 to an anti-jack knife device 46 constructed substantially in accordance with FIGURES 8 and 9. The anti-jack knife device 46 has an extension to the upper part of the coupling pin to which is secured a disc 48 so that the disc 48 is rotatable with the coupling pin.

' The disc 48 is formed with a cam 49 at a position on the periphery remote from the fluid inlet to the anti-jack knife device. The cam 49 cooperates with the push-rods of two push rod control valves 50 hereinafter described (FIGURE 13). The push rod control valves 50 are supplied with air from the emergency air-line 38 through air-line 51 which includes an air reservoir 52 and a limit valve 53. The air reservoir 52 incorporates a non-return valve (not shown) which prevents air from the air reservoir re-entering the emergency air-line 38 in the event of loss of pressure in the emergency air-line. Air delivery lines 54 from control valves 50 communicate through adouble check valve 55 and a common air line 56 with the double check valve 44.

Referring to FIGURE 12 of the drawings, the double check valves 44 and 45 each comprise a T-unionhaving two inlet ports 57 and a side outlet port 58'. The inlet ports 57 are each provided with an inwardly facing annular seating 59 adapted to engage with a shuttle valve 60. The shuttle valve 60 is slidable across the outlet port 58 to engage with one of the seatings 59 and to seal the corresponding inlet port 57 upon pressure being applied to the other inlet port 57.

Referring to FIGURE 13 of the drawings the push rod control valves 50 each comprise a body having a lower inlet port 61 sealed by an inlet valve 62, an internal port 63 and an outlet port 64.

The inlet valve 62 is connected to a spindle 65 which carries an exhaust valve 66 at the upper end. The exhaust valve 66'seats on the lower end of a hollow valve spindle 67 of a push rod 67a. A hollow duct 68 in spindle 67 connects to atmosphere. The inlet valve 62 is seated by a spring 62a. 7

On operation of the valve, if the valve spindle '67 is depressed by the push rod 670, the end of the spindle 67 seats on the valve 66 and seals the duct 68. Further downward movement opens the inlet valve 62 and air passes through the valve and out through the outlet port 64. If the spindle 67 is fully raised, the inlet valve 62 reseats 6 and the exhaust valve 66 opens. Air from the outlet line thus exhausts through duct 68 to atmosphere.

In operation of the system illustrated in FIGURE 11, depression of the foot brake (not shown) causes the service air line 37 to be pressurised. The brake cylinders 41 are operated through the emergency relay valve 40 to actuate the road Wheel brakes and the anti-jack knife device 46 is operated through connection 43, double check valve 44 and connection 45. The shuttle valve 60 of double check valve 44 prevents air from being discharged through the' connection 56. Release of the foot brake while the tractor and trailer are substantially aligned, causes simultaneous disengagement of the brakes and of the antijack knife device.

Articulation of the vehicle causes corresponding rotation of the disc 48 relatively to the push rod valves 50, until after a predetermined movement the push rod of one valve 50 rides up the corresponding side of the cam 49, dependent on the direction of articulation. The valve 50 opens and air passes from the air-line 51 through the double check valve 55 and connection 56 to the double check valve 44. Shuttle valve 60 of double check valve 44 also moves to seal the connection 43 and to permit operation of the anti-jack knife device. If the vehicle returns to the aligned position, the push rod of the operative push button valve 50 will lift and the air will be released from connection 45 and air-line 56 through the duct 68 of the valve spindle 67. The anti-jack knife will thus disengage.

Although the braking system described and illustrated in FIGURE 11 of the drawings incorporates an anti-jack knife device constructed in accordance with FIGURES 8 and 9, it is to be understood that any of the devices previously described may be used after suitable modification" to include the necessary cam surface. In the case of an anti-jack knife device utilising a disc and caliper, the cam surface 49 may be formed on the brake disc itself.

FIGURE 14 shows a further alternative braking system in which a service air-line 69 and an emergency air-line 70 are fed in known manner through tractor trailer couplings 71 and connect to an emergency relay valve 72.

The emergency relay valve 72 controls the supply of air to trailer brake air cylinders 73. Also connected to the emergency relay valve 72 is an air reservoir 74 which supplies air to the brakes in the event of failure of the air lines.

A branch air-line 75 from the service air-line 69 supplies air for the operation of an anti-jack knife device 77 through a double check valve 75e and air connection 76.

A pressure limiting valve 82 divides the service air-line 69 into sections 69a and 69b at a position intermediate the take off point for the branch air-line 75 and the emergency relay valve 72. The pressure limiting valve 82 is set to lift and to pass air to the emergency relay valve 72 at higher pressure than the pressure required to operate the anti jack knife device 77.

A further air line 75d connects the'service air line 70 with the second inlet port of the double check valve 752 through a pressure regulating valve 75c and a pilot air valve 75b. The pilot air valve 75b is a diaphragm type valve which opens when air pressure is applied though line 75a from line 75.

In operation, limited depression of a hand valve (not shown) by the driver causes the service air-line section 69a to be pressurised up to a pressure lower than the lifting pressure of the valve 82. This pressure is relayed through the branch air lines 75 and 75a to open the pilot air valve 75b. Air pressure from the emergency air line 70, regulated by valve 75:: is thus applied through line 75d andvia the double check valve 75e to the anti-jack device 77. I

Operation of theanti-jack knife device has thus been effected by limited operation of the braking system, but without application of the brakes. The hand valve may now be released to disengage the anti-jack knife device.

Alternatively, if the foot pedal or hand valve is depreSse-d still further, the higher air pressure entering the service air-line section 69a will lift the limiting valve 82.

The high pressure air will thus enter section 6912 of the service air-line 69 and operate the emergency relay valve 72 to apply the trailer brakes.

The higher pressure in line 69 will also act through line 75 upon double check valve 75e so as to close the second inlet port connected to line 70. The anti-jack knife device is then maintained in operation only by air pressure derived from line 69.

Release of the foot pedal or hand valve by the driver will release air pressure from section 69a of the service air-line 69 and thus from the anti-jack knife device 77 through the branch air-line 75. If desired the limiting valve 82 may be omitted in which case the road wheel brakes will be operated simultaneously with the anti-jack knife device.

FIGURE 15 shows the manner of connecting an antijack knife device in accordance with the invention into a three line pneumatic braking system in which a service airline 201, in auxiliary 202 and an emergency air-line 203 are fed in known manner to a tractor trailer coupling and connect to an emergency relay valve in known manner.

A branch air-line 204 from emergency air-line 203 is connected via a limiting valve 205 to one side of a pilot valve 206. Pilot valve 206 is arranged to control admission of air from emergency air-line 203 via a first double check valve 207 to an anti-jack knife device 208. Pilot valve 206 is controlled by an air-line 209 which is connected via a second double check valve 210 to the service air-line 201. The second double check valve 210 is also connected to the auxiliary air-line 202 and to the first double check valve 207. The braking system operates as follows. Under light braking conditions the service airline 201 is pressurised to a low pressure by the movement of the drivers foot onto the foot brake pedal and this causes the second double check valve 210 to slide left- Wardly as shown in the drawing and admit air from line 201 through line 209 to the pilot valve 206. This low pres sure signal causes the pilot valve 206 to open and admit air from the emergency air-line at a pressure suflicient to operate the anti-jack knife device 208 to the double check valve 207. The pressure of air admitted from the emergency air-line 203 causes the first double check valve 207 to move downwardly as shown in the drawing and this allows the air to be admitted to the anti-jack knife device 208 and cause it to operate.

Should the driver apply the vehicle road wheel brakes at maximum braking pressure, the double check valve 210 is moved rightwardly as shown in the drawing by the high pressure generated in the auxiliary air-line 202, Air is then passes from air-line 202 to the first double check valve 207 and then into the anti-jack knife device 208.

Referring to FIGURES 16 and 17, these figures show an anti-jack knife device fitted to the fifth wheel rather than to the coupling pin. A fifth Wheel 301 is fixedly secured to a plate 302 by means of trunnions 303. Plate 302 is secured at its base to a drum 304 by means of an outwardly extending flange 305 integral with the drum 304. Drum 304 is arranged to be rotatable within a ring 306, a bearing 307 comprising a ring of ball bearings being disposed between flange 305 and ring 306. Ring 306 is hollowed out to provide an annular chamber 308 for receiving an annular piston 309. Annular piston 309 carries a series of outwardly extending dowel pins 310 which locate in sleeves formed in the inner wall of chamber 308 so that the piston cannot rotate in the chamber 308 but is slidable vertically therein. Flange 305 overlays the mouth of chamber 308 and the underside of the overlying portion of flange 305 is provided with an annular friction face 311. One or more air inlets 312 are provided in the base of chamber 308 for the admission of fluid under pressure.

Referring to FIGURE 17, forwardly of the fifth wheel 301 and mounted on the plate 302 is a pin 313 which is arranged to engage with a slot in the underside of the trailer when the trailer and tractor are coupled together so that with the pin 313 engaging in the slot of the trailer articulates with the fifth wheel 301. Pin 313 is pivotable about a point 314 and is provided with centralising springs 315.

Thus in operation when a trailer is coupled with the fifth wheel it articulates with the fifth wheel and pivotal movement between the trailer and to the tractor is accommodated by rotation of the fifth wheel and its associated drum 304 in the ring 306. When it is desired to resist the relative turning between the trailer and the tractor air is admitted through inlet 312 into chamber 308. This has the effect of forcing the piston member 309 upwardly into engagement with the friction face 311 secured to the underside of flange 305. In consequence since piston member 309 cannot rotate the turning movement of flange 305 and therefore fifth wheel 301 is resisted.

We claim:

1. In an articulated vehicle including a tractor unit and a trailer unit, the brake system comprising, in combination: vehicle braking means; fifth wheel coupling means for resisting jack knife movement including a fifth wheel mounted on said tractor unit and coupling pin means establishing a draft connection between said tractor and trailer units, said coupling pin means including means for effecting non-rotatable engagement between the coupling pin and said fifth wheel, one of said fifth wheel and said coupling pin being mounted for rotational movement; braking means for resisting rotation of the rotatably mounted portion of said fifth wheel coupling mechanism to thereby resist jack knife movement of said articulated vehicle, said braking means including a first flat annular braking surface adapted to be mounted on one of said vehicles so as to be non-rotatable therewith, a second flat braking surface fixed with respect to the rotatably mounted portion of said fifth-wheel coupling means, said first annular braking surface further adapted to be movable into face to face engagement with said second braking surface, whereby upon actuation of said braking means rotation of said fifth wheel coupling means is resisted; and fluid pressure means for actuating said braking means of said fifth wheel coupling means and said vehicle braking means. i

2. In an articulated vehicle including a tractor unit and a trailer unit, the brake system of the vehicle, comprising, in combination: vehicle braking means; fifth wheel coupling means for resisting jack knife movement, including a fifth wheel adapted to be fixedly secured to said tractor unit, a coupling pin adapted to be rotatably mounted at its upper end in said trailer unit, and means for effecting non-rotatable engagement of said coupling pin at its lower end with said fifth wheel; braking means for resisting rotation of said coupling pin to thereby resist jack knife movement of said articulated vehicle, said braking means including at least one first flat braking surface mounted on said coupling pin so as to be non-rotatable relative thereto, at least one second flat braking surface adapted to be mounted so as to be non-rotatable relative to said trailer, and at least one of said first and second flat braking surfaces being movable into face to face engagement with the other of said braking surfaces upon actuation of the braking means; and fluid pressure means for actuating said braking means of said fifth wheel coupling means and said vehicle braking means.

3. In an articulated vehicle including a tractor unit and a trailer unit, the brake system of the vehicle, comprising, in combination: vehicle braking means; fifth wheel coupling means for resisting jack knife movement, including a fifth wheel adapted to be rotatably mounted on said tractor unit, a coupling pin adapted to be fixedly secured at its upper end to said trailer unit, and means for effecting non-rotatable engagement of said coupling pin at its lower end with sail fifth wheel; braking means for resisting rotation of said fifth wheel to thereby resist jack knife movement of said articulated vehicle, said braking means including a first flat annular braking surface adapted to be mounted on said tractor so as to be non-rotatable therewith, a second flat braking surface fixed with respect to said fifth wheel, said first annular braking surface further adapted to be movable into face to face engagement With said second, braking surface, whereby upon actuation of said braking means rotation of said fifth wheel is resisted; and fluid pressure means for actuating said braking means of said fifth wheel coupling means and said vehicle braking means 4. In an articulated vehicle including a tractor unit and a trailer unit, apparatus for resisting jack knife movement of the vehicle, comprising, in combination: fifth wheel coupling mechanism, including a fifth wheel adapted to be fixedly secured to said tractor unit, a coupling .pin adapted to be rotatably mounted at its upper end in said trailer unit, and means for effecting non-rotatable engagement of said coupling pin at its lower end with said fifth wheel; braking means for resisting rotation of said coupling pin to thereby resist jack knife movement of said articulated vehicle, said braking means including a plurality of first annular disks which are mounted on the upper end of said coupling pin so as to be slidable axially but non-rotatable with respect thereto, at least one pair of adjacent coupling pin disks having interposed therebetween a second annular disk which is mounted on said trailer unit so as to be slidable in the same direction as said first annular disks but non-rotatable with respect to said trailer unit; and fluid pressure means for actuating the stack of disks into compressed facing engagement thereby resisting rotation of said coupling pin, said fluid pressure means including a pressurized two-line system comprising a service line and an emergency line for actuating both the vehicle road wheel brakes and the fifth wheel coupling braking means, said fifth Wheel coupling braking means being connected to said service line and said emergency line by means of a double check valve whereby said braking means may be operated by either of said lines, and a pressure detector valve connected across said double check valve and arranged so as to pass fluid from said emergency line to said fifth wheel coupling braking means on application of the vehicle road wheel brakes When the pressure in said service line is insuflicient to operate said fifth wheel coupling braking means.

5. In an articulated vehicle including a tractor unit and a trailer unit, apparatus for resisting jack knife movement of the vehicle, comprising, in combination: fifth wheel coupling mechanism, including a fifth wheel adapted to be fixedly secured to said tractor unit, a coupling pin adapted to be rotatably mounted at its upper end in said trailer unit, and means for effecting non-rotatable engagement of said coupling pin at its lower end with said fifth wheel; braking maens for resisting rotation of said coupling pin to thereby resist jack knife movement of said articulated vehicle, said braking means including a plurality of first annular disks which are mounted on the upper end of said coupling pin so as to be slidable axially but non-rotatable with respect thereto, at least one pair of adjacent coupling pin disks having interposed therebetween a second annular disk which is mounted on said trailer unit so as to be slidable in the same direction as said first annular disks but non-rotatable with respect to said trailer unit; and fluid pressure means for actuating the stack of disks into compressed facing engagement thereby resisting rotation of said coupling pin, said fluid pressure means including a pressurized three-line system comprising a service line, an emergency line and an auxiliary line, said service and emergency lines adapted to normally actuate both the vehicle road wheel brakes and the fifth wheel coupling braking means, said fifth wheel coupling braking means being connected to said service line and said emergency line by means of a first double check valve whereby said braking means may be operated by either of said lines and a pressure detector valve connected across said double check valve and arranged so as to pass fluid from said emergency line to said fifth wheel coupling braking means on application of the vehicle road wheel brakes when the pressure in said service line is insufiicient to operate said fifth wheel coupling braking means, said auxiliary air-line being connected into the service line feed to said fifth wheel coupling braking means by means of a second double check valve, whereby under maximum application of the vehicle road wheel brakes, said second double check valve isolates said fifth Wheel coupling braking means from said service line and said fifth wheel coupling braking means is actuated by fluid pressure in said auxiliary line.

6. A fifth wheel coupling for an articulated vehicle comprising a tractor and trailer and having means for resisting jack knife movement of the vehicle, said coupling comprising:

a fifth wheel adapted to be rotatably mounted on said tractor;

a coupling pin adapted to be fixedly secured at its upper end to said trailer;

means for effecting non-rotatable engagement of said coupling pin at its lower end with said fifth wheel; and

braking means including a first flat annular braking surface adapted to be mounted on said tractor so as to be non-rotatable therewith,

a second flat braking surface fixed with respect to said fifth wheel,

said first annular braking surface further adapted to be slidable into face to face engagement with said second braking surface,

whereby upon actuation of said braking means rotation of said fifth wheel is resisted.

7. A fifth wheel coupling for an articulated vehicle comprising a tractor and trailer and having means for resisting jack knife movement of the vehicle, said coupling comprising:

a fifth wheel adapted to be fixedly secured to said tractor;

a coupling pin adapted to be rotatably mounted at its upper end in said trailer;

means for effecting non-rotatable engagement of said coupling pin at its lower end with said fifth wheel; and

braking means including at least one first fiat braking surface mounted on said coupling pin so as to be non-rotatable relative thereto,

at least one second flat braking surface adapted to be mounted so as to be non-rotatable relative to said trailer, and

at least one of said first and second flat braking surfaces being slidable into face to face engagement with the other of said braking surfaces upon actuation of the braking means.

8. A coupling as claimed in claim 7, wherein said first and second flat braking surfaces are contained within a casing,

said casing having means for the introduction of fluid under pressure between said slidable braking surface and said casing,

whereby said slidable braking surface is moved into grictional engagement with said other braking surace.

9. A coupling as claimed in claim 7, wherein said means for effecting non-rotatable engagement of said coupling pin with the fifth wheel comprises a tongue secured to the lower end of said coupling pin and extending laterally therefrom, said tongue being engageable in the fifth wheel slot.

10. A coupling as claimed in claim 7, wherein said braking means further includes fluid pressure means, including a supply of fluid under pressure, operating means comprising a cam secured to said coupling pin, and cam followers forming the actuating plungers of fluid control valves which are positioned between said fluid supply and said braking means, whereby rotation of said cam with said coupling pin controls the application of pressurized fluid to said braking means. 11. A coupling as claimed in claim 8, wherein said first flat braking surface comprises annular disks which are slidable axially but non-rotatable with respect to said coupling pin; said second flat braking surface comprises annular disks adapted to be mounted on said trailer so as to be slidable in the same direction as said first annular disks but non-rotatable with respect to said trailer; at least one pair of adjacent first annular disks having interposed therebetween a second annular disk; and means for compressing said first and second annular disks together, whereby turning movement of said coupling pin is resisted. 12. A coupling as claimed in claim 11, wherein said casing containing said disks is adapted to be secured to said trailer, and

12. said second annular disk is attached to said casing. 13. A coupling as claimed in claim 11, wherein said means for compressing said disks comprises an annular piston member disposed in said casing, and means for moving said piston member into engagement with said stack to thereby compress the disks together. 14, A coupling as claimed in claim 13, wherein said casing includes an inlet disposed between said piston member and one end of said casing,

and including means for admitting fluid under pressure through said inlet so as to cause said piston member to compress said disks together.

References Cited UNITED STATES PATENTS 2,213,221 9/1940 Johnson 280432 2,613,946 10/1952 Anderson et al. 280432 3,036,845 5/1962 Till 280432 3,063,739 11/1962 Davies 280432 X 3,231,295 1/1966 Till 280432 LEO FRIAGLIA, Primary Examiner. 

1. IN AN ARTICULATED VEHICLE INCLUDING A TRACTOR UNIT AND A TRAILER UNIT, THE BRAKE SYSTEM COMPRISING, IN COMBINATION; VEHICLE BRAKING MEANS; FIFTH WHEEL COUPLING MEANS FOR RESISTING JACK KNIFE MOVEMENT INCLUDING A FIFTH WHEEL MOUNTED ON SAID TRACTOR UNIT AND COUPLING PIN MEANS ESTABLISHING A DRAFT CONNECTION BETWEEN SAID TRACTOR AND TRAILER UNITS, SAID COUPLING PIN MEANS INCLUDING MEANS FOR EFFECTING NON-ROTATABLE ENGAGEMENT BETWEEN THE COUPLING PIN AND SAID FIFTH WHEEL, ONE OF SAID FIFTH WHEEL AND SAID COUPLING PIN BEING MOUNTED FOR ROTATIONAL MOVEMENT; BRAKING MEANS FOR RESISTING ROTATION OF THE ROTATABLY MOUNTED PORTION OF SAID FIFTH WHEEL COUPLING MECHANISM TO THEREBY RESIST JACK KNIFE MOVEMENT OF SAID ARTICULATED VEHICLE, SAID BRAKING MEANS INCLUDING A FIRST FLAT ANNULAR BRAKING SURFACE ADAPTED TO BE MOUNTED ON ONE OF SAID VEHICLES SO AS TO BE NON-ROTATABLE THEREWITH, A SECOND FLAT BRAKING SURFACE FIXED WITH RESPECT TO THE ROTATABLY MOUNTED PORTION OF SAID FIFTH-WHEEL COUPLING MEANS, SAID FIRST ANNULAR BRAKING SURFACE FURTHER ADAPTED TO BE MOVABLE INTO FACE TO FACE ENGAGEMENT WITH SAID SECOND BRAKING SURFACE, WHEREBY UPON ACTUATION OF SAID BRAKING MEANS ROTATION OF SAID FIFTH WHEEL COUPLING MEANS IS RESISTED; AND FLUID PRESSURE MEANS FOR ACTUATING SAID BRAKING MEANS OF SAID FIFTH WHEEL COUPLING MEANS AND SAID VEHICLE BRAKING MEANS. 